#!/usr/bin/env bash
#
# This script can make a customized bootable image of Windows PE.
#

# Copyright (C) 2012, 2013 Eric Biggers
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

script_name="$(basename "$0")"
PREFIX_REG="::"
WIMLIB_VERSION=@VERSION@

calc_columns () {
	STAT_COL=80
	if [[ -t 0 ]]; then
		# stty will fail when stdin isn't a terminal
		STAT_COL=$(stty size)
		# stty gives "rows cols"; strip the rows number, we just want columns
		STAT_COL=${STAT_COL##* }
	elif tput cols &>/dev/null; then
		# is /usr/share/terminfo already mounted, and TERM recognized?
		STAT_COL=$(tput cols)
	fi
	if (( STAT_COL == 0 )); then
		# if output was 0 (serial console), set default width to 80
		STAT_COL=80
	fi

	# we use 13 characters for our own stuff
	STAT_COL=$(( STAT_COL - 13 ))

	if [[ -t 1 ]]; then
		SAVE_POSITION="\e[s"
		RESTORE_POSITION="\e[u"
		DEL_TEXT="\e[$(( STAT_COL + 4 ))G"
	else
		SAVE_POSITION=""
		RESTORE_POSITION=""
		DEL_TEXT=""
	fi
}


deltext() {
	printf "${DEL_TEXT}"
}

stat_busy() {
	printf "${PREFIX_REG} ${1} "
	printf "${SAVE_POSITION}"
	deltext
	printf "   [BUSY] "
}

stat_done() {
	deltext
	printf "   [DONE] \n"
}

stat_fail() {
	deltext
	printf "   [FAIL] \n"
	exit 1
}


cleanup() {
	rm -rf "$tmp_dir"
}

usage() {
	cat << EOF
Usage: $script_name [OPTIONS] IMAGE

  -i, --iso                Make an ISO image instead of a disk image.
  -o, --only-wim           Make neither a disk image nor an ISO image;
                              instead, only make a modified boot.wim file.
  -W, --windows-dir=DIR    Use DIR as the location of the mounted Windows
                              installation ISO image.  If not specified, then
                              the script tries the following locations:
                              /mnt/windows, /mnt/windows7, /mnt/windows8,
                              /mnt/windows10.
  -A, --waik-dir=DIR       Get the boot files and boot.wim from the ISO image
                              of the Windows Automated Installation Kit (WAIK)
                              mounted on DIR instead of from a Windows
                              installation ISO.  This also works if the mounted
                              ISO is for the WAIK supplement rather than for the
                              WAIK itself.
  -s, --start-script=FILE  Add FILE to the root directory of Windows PE image
                              and adjust \Windows\System32\winpeshl.ini to
                              execute FILE when Windows PE starts up.
  -w, --wim=WIM            Use WIM as the boot.wim file.  This defaults to the
                              appropriate WIM file from the Windows or WAIK
                              directory.
  -O, --overlay=DIR        Adds all the files in DIR to the Windows PE image.
  -t, --tmp-dir=DIR        Use DIR as the temporary base of the ISO filesystem.
                              Defaults to making one using "mktemp -d".
  -a, --arch=ARCH          Use the Windows PE version from the WAIK that has
                              the CPU architecture ARCH.  Possible values:
                              "x86" or "amd64".  Default is "x86".
  -h, --help               Display this information.
  -v, --version            Show version information.

  See \`man mkwinpeimg' for more information.
EOF
}

version() {
	echo "$script_name (distributed with wimlib $WIMLIB_VERSION)"
	exit 0
}

make=disk

process_command_line() {

	if ! options=$(getopt -o oiw:W:s:O:t:A:a:hv -l \
		only-wim,iso,wim:,windows-dir:,start-script:,overlay:,tmp-dir:,waik-dir:,arch:,help,version \
				-- "$@" ); then
		usage
		exit 1
	fi

	# default arch value
	arch="X86"
	arch_id="1"

	eval set -- "$options"
	while [ $# -gt 0 ]; do
		case "$1" in
		-i|--iso)
			make=iso
			;;
		-o|--only-wim)
			make=wim
			;;
		-W|--windows-dir)
			windows_dir="$2"
			windows_dir_specified=yes
			if [ -n "$waik_dir" ]; then
				echo 1>&2 "ERROR: Cannot specify both --windows-dir and --waik-dir!"
				exit 1
			fi
			shift
			;;
		-A|--waik-dir)
			waik_dir="$2"
			if [ -n "$windows_dir" ]; then
				echo 1>&2 "ERROR: Cannot specify both --windows-dir and --waik-dir!"
				exit 1
			fi
			shift
			;;
		-w|--wim)
			wim="$2"
			shift
			;;
		-s|--start-script)
			start_script="$2"
			shift
			;;
		-O|--overlay)
			overlay="$2"
			shift
			;;
		-t|--tmp-dir)
			rmdir "$tmp_dir"
			tmp_dir="$2"
			shift
			;;
		-a|--arch)
			if [ "$2" == "x86" ]; then
				arch="X86"
				arch_id="1"
			# Need to test Itanium images before making it an
			# option.  Note: syslinux is x86 only so can't be used
			# for the Itanium disk image.
			#elif [ "$2" == "ia64" ]; then
				#arch="IA64"
				#arch_id="2"
			elif [ "$2" == "amd64" ]; then
				arch="AMD64"
				arch_id="3"
			else
				echo 1>&2 "ERROR: $2 is not a valid arch (x86/amd64)"
				exit 1
			fi
			shift
			;;
		-h|--help)
			usage
			exit 0
			;;
		-v|--version)
			version
			;;
		--)
			shift
			break
			;;
		*)
			echo 1>&2 "Invalid option \"$1\""
			usage
			exit 1
			;;
		esac
		shift
	done

	if [ $# -ne 1 ]; then
		echo 1>&2 "You must specify the name of the image file to create!"
		echo 1>&2 "Run \"$script_name -h\" to see usage information."
		exit 1
	else
		image="$1"
	fi
}

find_windows_dir() {
	if [ -z "$windows_dir_specified" ]; then
		for windows_dir in /mnt/windows /mnt/windows7		\
				   /mnt/windows8 /mnt/windows10;	\
		do
			if [ -d "$windows_dir"/sources ]; then
				break
			fi
		done
	fi
	if [ ! -d "$windows_dir" ]; then
		if [ -z "$windows_dir_specified" ]; then
			cat 1>&2 << EOF
ERROR: Could not find the directory that the Windows (Vista or later) ISO image
is mounted on!  Please specify this directory using the --windows-dir option.
EOF
		else
			echo 1>&2 "ERROR: Could not find the directory \"$windows_dir\"!"
		fi
		exit 1
	fi
	if [ ! -d "$windows_dir/sources" ]; then
		cat 1>&2 << EOF
ERROR: The directory "$windows_dir" exists, but it seems that a Windows
(Vista or later) installation ISO image is not mounted on it.  Please mount
the image to continue.
EOF
		exit 1
	fi
}

check_needed_programs() {
	if [ -z "$waik_dir" -o -n "$modify_wim" ]; then
		if ! type -P wimlib-imagex &> /dev/null ; then
			cat 1>&2 << EOF
ERROR: To make a customized image of Windows PE, we need the wimlib-imagex program
from "wimlib" so that we can modify the boot.wim file.  However, wimlib-imagex
doesn't seem to be installed.  Please install "wimlib" to continue.
EOF
			exit 1
		fi
	fi

	if [ $make = iso ]; then
		if ! type -P mkisofs &> /dev/null ; then
			cat 1>&2 << EOF
ERROR: To make a bootable ISO image of Windows PE, we need the "mkisofs"
program, but it doesn't seem to be installed.  Please install the "cdrkit"
package to continue, or try omitting the --iso option to make a disk image
instead of an ISO image.
EOF
			exit 1
		fi
	elif [ $make = disk ] ; then
		if ! type -P syslinux &> /dev/null ; then
			cat 1>&2 << EOF
ERROR: To make a bootable disk image of Windows PE, we need the "syslinux"
program, but it doesn't seem to be installed.  Please install the "syslinux"
package to continue, or try using the --iso option to make an ISO image instead
of a disk image.
EOF
			exit 1
		fi

		if ! type -P mformat mcopy &> /dev/null; then
			cat 1>&2 << EOF
ERROR: To make a bootable disk image of Windows PE, we need the "mformat" and
"mcopy" programs from the "mtools" package.  These programs allow us to
format a FAT filesystem and copy files to it without needing root privileges.
Please install "mtools" if you want to make a disk image of Windows PE.  Or,
try using the --iso option to make an ISO image instead of a disk image.
EOF
		fi
	fi

	if [ -n "$waik_dir" ] &&  [ -f "$waik_dir"/wAIK${arch}.msi ]; then
		if ! type -P cabextract &> /dev/null ; then
			cat 1>&2 << EOF
ERROR: The boot files in the Windows Automated Installation Kit (WAIK) are
inside cabinet archives.  To extract these files, we need the "cabextract"
program, but it doesn't seem to be installed.  Please install "cabextract" to
continue.
EOF
			exit 1
		fi
	fi

}

get_primary_boot_files() {
	if [ -n "$waik_dir" ]; then
		# Get boot files from the WAIK.
		stat_busy "Copying primary boot files from the Windows Automated Installation Kit ($waik_dir, $arch)"

		if [ -f "$waik_dir"/wAIK${arch}.msi ]; then
			if [ $make = iso ]; then
				cabextract "$waik_dir"/wAIK${arch}.msi -F F_WINPE_${arch}_etfsboot.com -p \
						> "$tmp_dir"/etfsboot.com || stat_fail
			fi
			cabextract "$waik_dir"/wAIK${arch}.msi -F F${arch_id}_BOOTMGR -p \
					> "$tmp_dir"/bootmgr || stat_fail
			cabextract "$waik_dir"/wAIK${arch}.msi -F F_WINPE_${arch}_boot.sdi -p \
					> "$tmp_dir"/boot/boot.sdi || stat_fail
			cabextract "$waik_dir"/wAIK${arch}.msi -F F_WINPE_${arch}_bcd -p \
					> "$tmp_dir"/boot/bcd || stat_fail
		# The WAIK supplement disc has a different structure
		else
			# Note: fuseiso, mount default to map=normal i.e. lowercase
			if [ $make = iso ]; then
				cp "$waik_dir"/${arch,,}/boot/etfsboot.com $tmp_dir/etfsboot.com || stat_fail
			fi
			cp "$waik_dir"/${arch,,}/bootmgr $tmp_dir/bootmgr || stat_fail
			cp "$waik_dir"/${arch,,}/boot/boot.sdi $tmp_dir/boot/boot.sdi || stat_fail
			cp "$waik_dir"/${arch,,}/boot/bcd $tmp_dir/boot/bcd || stat_fail
		fi
		stat_done
	else
		# Get boot files from the Windows ISO

		stat_busy "Copying primary boot files from mounted Windows ISO ($windows_dir)"
		if [ $make = iso ]; then
			cp "$windows_dir"/boot/etfsboot.com "$tmp_dir" || stat_fail
		fi
		cp "$windows_dir"/bootmgr "$tmp_dir" || stat_fail
		cp "$windows_dir"/boot/{bcd,boot.sdi} "$tmp_dir"/boot || stat_fail
		stat_done
	fi
}

get_boot_wim() {
	boot_wim="$1"
	# Copy the WIM over, or export the 2nd image in the WIM in the case of boot.wim
	# from the Windows ISO.
	remove_setup=
	if [ -z "$wim" ]; then

		# WIM file unspecified- grab it from the WAIK or the Windows ISO
		if [ -n "$waik_dir" ]; then
			# WAIK
			if [ -f "$waik_dir/WinPE.cab" ]; then
				stat_busy "Extracting boot.wim from \"$waik_dir/WinPE.cab\""
				cabextract "$waik_dir/WinPE.cab" -F F${arch_id}_WINPE.WIM -p \
						> "$boot_wim" 2>/dev/null || stat_fail
			# WAIK supplement has different layout
			else
				stat_busy "Copying boot.wim from \"${waik_dir}/${arch,,}/winpe.wim\""
				cp "$waik_dir"/${arch,,}/winpe.wim "$boot_wim" || stat_fail
				chmod +w "$boot_wim"
			fi
			stat_done
		else
			# Windows ISO
			remove_setup=yes
			wim="$windows_dir/sources/boot.wim"
			stat_busy "Exporting image from \"$wim\""
			wimlib-imagex export "$windows_dir"/sources/boot.wim 2 \
						--boot "$boot_wim" || stat_fail
			stat_done
		fi
	else
		# WIM file specified
		stat_busy "Copying $wim to temporary directory"
		cp "$wim" "$boot_wim"|| stat_fail
		stat_done
	fi
}

# Make modifications to the WIM.
modify_boot_wim() {
	boot_wim="$1"
	tmp_dir="$2"

	exec 3>"$tmp_dir/__mkwinpeimg.update.cmds"

	if [ -n "$remove_setup" ]; then
		stat_busy "Renaming setup.exe to prevent it from bothering us"
		cat 1>&3 <<- EOF
			rename /setup.exe /setup.exe.orig
			rename /sources/setup.exe /sources/setup.exe.orig
		EOF
		stat_done
	fi

	if [ -n "$start_script" ]; then
		stat_busy "Setting \"$start_script\" as the script to be executed when Windows PE boots"
		start_script_base="$(basename "$start_script")"
		cat > "$tmp_dir/__mkwinpeimg.winpeshl.ini" <<- EOF
			[LaunchApps]
			%SYSTEMDRIVE%\\$start_script_base
		EOF
		cat 1>&3 <<- EOF
			add '$start_script' '/$start_script_base'
			delete --force /Windows/System32/winpeshl.ini
			add '$tmp_dir/__mkwinpeimg.winpeshl.ini' /Windows/System32/winpeshl.ini
		EOF
		stat_done
	fi

	if [ -n "$overlay" ]; then
		stat_busy "Overlaying \"$overlay\" on the Windows PE filesystem"
		cat 1>&3 <<- EOF
			add '$overlay' /
		EOF
		stat_done
	fi

	exec 3>&-

	stat_busy "Rebuilding WIM with changes made"
	# Use case-insensitive mode; some Windows PE images contain a "windows"
	# directory instead of a "Windows" directory...
	WIMLIB_IMAGEX_IGNORE_CASE=1 wimlib-imagex update "$boot_wim" --rebuild \
		< "$tmp_dir/__mkwinpeimg.update.cmds" > /dev/null || stat_fail
	stat_done
}

make_iso_img() {
	image="$1"

	# Make the ISO using the mkisofs command from cdrkit

	stat_busy "Making ISO image \"$image\""

	mkisofs -sysid ""  -A ""  -V "Microsoft Windows PE ($arch)"  -d -N \
		-b etfsboot.com  -no-emul-boot   -c boot.cat  -hide etfsboot.com  \
		-hide boot.cat -quiet -o "$image" "$tmp_dir" 1>&4 || stat_fail

	stat_done
}

make_disk_img() {
	image="$1"

	stat_busy "Making disk image \"$image\""

	image_du=$(du -s -b "$tmp_dir" | cut -f 1)
	image_size=$(( image_du + 10000000 ))

	mtool_conf="$(mktemp)"

	dd if=/dev/zero of="$image" count=$(( (image_size + 4095) / 4096)) \
			bs=4096 &> /dev/null

	cat > "$mtool_conf" <<- EOF
		MTOOLS_SKIP_CHECK=1
		MTOOLS_FAT_COMPATIBILITY=1
		drive s:
			file="$image"
	EOF

	export MTOOLSRC="$mtool_conf"

	mformat -h 255 -s 63 -T $(( image_size / 512)) s: || stat_fail
	mcopy -s "$tmp_dir"/* s: || stat_fail

	syslinux --install "$image"

	for biosdir in				\
		/usr/lib/syslinux/modules/bios	\
		/usr/lib/syslinux/bios		\
		/usr/lib/syslinux		\
		/usr/share/syslinux
	do
		if [ -e "$biosdir/chain.c32" ]; then
			break
		fi
	done

	mcopy "$biosdir/chain.c32" s: || stat_fail
	if [ -e "$biosdir/libcom32.c32" ]; then
		mcopy "$biosdir/libcom32.c32" s:
	fi
	if [ -e "$biosdir/libutil.c32" ]; then
		mcopy "$biosdir/libutil.c32" s:
	fi
	mcopy - 's:syslinux.cfg' <<- EOF
		DEFAULT winpe
		LABEL	winpe
		COM32	chain.c32
		APPEND	ntldr=/bootmgr
	EOF
	rm -f "$mtool_conf"
	stat_done
}

calc_columns
tmp_dir="$(mktemp -d)"
process_command_line "$@"

if [ "$image" = "-" ] ; then
	# Writing image to standard output
	if [ "$make" != iso ]; then
		echo 1>&2 "ERROR: Writing image to standard output is only supported in --iso mode!"
		exit 1
	fi
	# We can't print anything to standard output except the ISO image
	# itself.  Play with the file descriptors.

	exec 4>&1  # 4 is now the original standard output.
	exec 1>&2  # Anything that goes to standard output now, by default,
		   # actually goes to standard error.
else
	exec 4>&1  # 4 is now a copy of standard output
fi
if [ -z "$waik_dir" ]; then
	find_windows_dir
fi
if [ -n "$start_script" -o -n "$overlay" -o -n "$remove_setup" ]; then
	modify_wim=yes
fi
check_needed_programs
trap cleanup EXIT

if [ $make != wim ]; then
	mkdir -p "$tmp_dir"/{boot,sources}
	get_primary_boot_files
fi

if [ $make = wim ]; then
	boot_wim="$image"
else
	boot_wim="$tmp_dir"/sources/boot.wim
fi

get_boot_wim "$boot_wim"

if [ -n "$modify_wim" ]; then
	modify_boot_wim "$boot_wim" "$tmp_dir"
fi

if [ $make = iso ]; then
	make_iso_img "$image"
elif [ $make = disk ]; then
	make_disk_img "$image"
fi

if [ "$image" != "-" ]; then
	echo "The image ($image) is $(stat -c %s "$image") bytes."
fi
